[DOCS] Overview validation messages used in EXT:form

The documentation now includes an overview of the used validation
messages and their error codes. While being on it, the DateRange
validator has been documented as well.

Resolves: #87393
Releases: main, 11.5
Change-Id: I5e91131d5464fde370609310a2a5a5a3b64941c7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73714


Tested-by: Elias Häußler <e.haeussler@familie-redlich.de>
Tested-by: waldhacker <hello@waldhacker.dev>
Reviewed-by: Elias Häußler <e.haeussler@familie-redlich.de>
Reviewed-by: waldhacker <hello@waldhacker.dev>